1. Field of the Invention
The present invention relates to a map distributing device, a map acquiring device, a map processing system, a map distributing method, a map acquiring method, a map processing program, and a recording medium storing the map processing program, each updating map information related to a map.
2. Description of Related Art
Conventionally, there has been known a navigation device that updates old map information to new map information (e.g., see Document 1: JP-A-2001-141473, pages 3 to 4, FIGS. 2 and 5).
The device disclosed in Document 1 allows a usage period calculator to specify a creation period of map data to calculate a usage period up to the present from the creation period. Then the device allows an expression changer to change an expression according to the usage period, namely, the longer the usage period of the map is, the more unclearly the device allows a display section to display, so that a user may find that the map has been old.
Incidentally, the conventional configuration in Document 1 processes for changing the expression of map information displayed on the display section according to how old the map is. However, according to the configuration, the user can recognize that the map has been old, but can not recognize information related to updated contents of the new map. And, when updating the map, the user generally needs to purchase new map information via a network or a recording medium. Therefore, the user can check the updated contents of the new map information only after the purchase of the new map information. Thus, even though the user purchases the new map information, the user may not acquire desired map information.